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2 years ago

3. How many protons are in the following elements?

Chemistry

1 answer:

Nikolay [14]2 years ago

7 0

Explanation:

carbon=6

hydrogen=1

oxygen=8

phosphorus=15

calcium=20

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If 12.6 grams of iron (III) oxide reacts with 9.65 grams of carbon monoxide to produce 7.23 g of pure iron, what are the theoret

Mariana [72]

The balanced equation is Fe₂O₃ + 3 CO = 2 Fe + 3 CO₂.
Next step is to convert everything to moles.
12.6g Fe₂O₃ x (1 mol Fe₂O₃ / 159.7g Fe₂O₃) = 0.07890 mol Fe₂O₃
9.65g CO x (1 mol CO / 28.01g CO) = 0.3445 mol CO
The third step is to determine the limiting and excess reactants.
0.07890 mol Fe₂O₃ x (3 mol CO/1 mol Fe₂O₃) = 0.2367 mol CO
Therefore Fe₂O₃ is the limiting reagent while CO is in excess.

0.07890 mol Fe x (2 mol Fe(s) / 1 mol Fe₂O₃) = 0.1578 mol Fe(s)
0.1578 mol Fe x (55.84g Fe / mole Fe) = 8.812g Fe is the theoretical yield
%yield = (7.23g / 8.812g) x 100% = 82.0% is the percent yield

3 0

3 years ago

Please help with this

dlinn [17]

Answer:

A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is 0.67 atm.

Step by Step Explanation?

Boyle's law states that in constant temperature the variation volume of gas is inversely proportional to the applied pressure.

The formula is,

P₁ x V₁ = P₂ × V₂

Where,

P₁ is initial pressure = 1 atm

P2 is final pressure = ? (Not Known)

V₁ is initial volume = 10 L

V₂ is final volume = 15 L

Now put the values in the formula,

\begin{gathered}\rm 1\times 10 = P_2\times 15\\\\\rm P_2 = \frac{10}{15\\} \\\\\rm P_2 = 0.67\end{gathered]

Therefore, the answer is 0.67 atm.

5 0

2 years ago

Read 2 more answers

Unit 1- Unit Assessment (Matter & Density)

konstantin123 [22]

Answer:

<h3>The answer is 11 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 3025 g

volume = 275 mL

We have

$density = \frac{3025}{275} \\$

We have the final answer as

Hope this helps you

7 0

2 years ago

A fog over a lake. what two changes of state must occur to produce the fog? do the water molecules absorb or release energy duri

Zolol [24]

The water from the lake must first evaporate from the liquid state to the gaseous state and then condense in the air to form vapors.
The water molecules absorb energy while evaporating and release it when condensing. Their motion gets faster when they are evaporating and slows back down upon condensation.

3 0

2 years ago

Read 2 more answers

What is the ph of a 0.014 M HCL solution?

Allushta [10]

Answer:

pH $= 1.853$

Explanation:

For every mole of hydrochloric acid, one mole of hydronium ion is required. Thus, in order to neutralize 0.014 moles of HCL, 0.014 moles of hydronium is required.

$[H_3O^+] = [HCl] = 0.014$

pH $= -log [H^+] = -log [H_3O^+]$

Substituting the available values in above equation, we can say that the pH of the solution is equal to

$- log (0.014)$

pH $= 1.853$

pH of a $0.014$ M HCL solution $= 1.853$

8 0

3 years ago